Magnet body for electromagnetic clutches especially of the stationary body type



March 30, 1965 H. STRAUB 3,176,193

MAGNET BODY FOR ELECTROMAGNETIC CLUTCHES ESPECIALLY OF THE STATIONARY BODY TYPE Filed April 17, 1961 F4 1 /a my. 4

United States Patent "ice 7 Claims. a. 317-458) This invention relates to magnet bodies of the type used in electromagnetic clutches and more particularly to clutches wherein the magnet body is maintained stationary and has connections thereto made Without the use of slip rings.

In magnet bodies of the kind described, the usual mode of construction is to manufacture a solenoid coil as a separate structural member and insert it into a groove or channel of the ferrous magnet body. Such solenoid coils have been manufactured by winding a wire on a form which is of the desired shape of the coil to be produced and subsequently potting the coil with a suitable compound such as plastic, etc. Upon removal of the winding form a solenoid coil or solenoid would result for insertion into the magnet body channel. After such insertion the channel is filled with a suitable compound whereby the solenoid is permanently fixed in the channel. Leads from the solenoid are brought out of the magnet body to be connected to a current source.

The above described conventional mode of construction has certain disadvantages. Thus, it is necessary to treat the solenoid coil during the course of manufacture and also after insertion in the magnet body channel with suitable potting or grouting compounds. Further, once the solenoid is in place in the magnet body it is permanently connected thereto and cannot be removed for purposes of repair should any defect occur. This, of course, results in not only an expensive manufacturing process, but also an expensive loss should the solenoid develop a defect, for the reason that the entire magnet body must be discarded.

It is an object of the present invention to overcome the above drawbacks of conventional methods and structures.

It is another object of the invention to provide a magnet body which can be simply and economically manufactured and which, for all practical purposes, will perform as satisfactorily as magnet bodies of the prior art and which will be rugged and strong in operation.

A still further object of the invention is to provide a magnet body which will be of compact construction and arranged and constructed for easy removal of the solenoid without the use of special tools.

Other objects and features of the invention will be apparent from the detailed description to follow.

Briefly, the invention comprises a magnet body having a channel for insertion of a solenoid. The solenoid, however, is wound within a channel of what may be termed an auxiliary magnet body or permanent winding form. Thus, such a body is provided with a large peripheral channel in which the wire is wound to form a solenoid coil and is then inserted in the radial channel of the magnet body and secured therein by means of screws. Accordingly, the solenoid may be readily removed for repair it necessary. Connections to the solenoid are readily arranged by means of detachable plug and socket devices.

A detailed description of the invention will now be given in conjunction with the appended drawing in which:

FIG. 1 is a longitudinal view, primarily in section, of

3,176,198 Patented Mar. 30, 1965 a magnet body and solenoid constructed in accordance with the teaching of the invention.

FIG. 2 is a section showing the solenoid wound in the channel of a ferrous ring or auxiliary magnet body ready for insertion into the magnet body, and which ring serves as a coil form which becomes a permanent part of the solenoid.

FIG. 3 is a plan view of the assembly; and

FIG. 4 is a fragmentary view showing details of the connecting means.

Referring now to the drawing, a housing 3 which carries magnet body 2 is disclosed, and it will be understood that the magnet body is of the stationary type, being secured by any suitable means to the housing. The magnet body has a solenoid mounted on a bushing 4 with intermediate needle bearing 5, which bushing is in turn carried on shaft 6, all of conventional construction for use either as a clutch or a brake.

The magnet body has a radial channel 14 for accommodating a channel ring 11 which may be regarded as an auxiliary magnet body or as a permanent winding form for a solenoid coil 13 shown as wound therein. Thus, in manufacture, the form 11, which is preferably of ferrous material, becomes a permanent part of the solenoid coil 13 and has affixed, as by welding, a plurality of collars 16 which are threaded at 19 to take screws 21 which pass through the back of magnet body 2 through bores 20. Collars 16 fit smoothly in bores 17 provided in the back wall 18 of the magnet body. It will thus be apparent that the solenoid and integral ring 11 can be firmly afiixed and keyed to magnet body 2 by means of screws 21 threaded into respective collars 16. It will likewise be apparent that the solenoid body ring 11 can be readily detached and removed from the magnet body.

In order to effect electrical connection to solenoid 13, a simple plug and socket arrangement is utilized. Thus, plug-in contact sockets 23 and 24 are formed in an insulated block 28 which is securely attached to the wall 22 of solenoid body ring 11. Within the sockets are respective metallic prongs 26 and 27 to co-act with respective plugs 33 and 34 which connect to lines 31 and 32. The arrangement is such that the insulated block 28 is substantially flush both with the back wall 18 of the magnet body and the periphery of the ring 11 when the ring 11 is inserted in the magnet body. Thus, the back wall 18 and the circumferential wall of the magnet body 2 are suitably notched at 35 to accommodate the insulating plug, as shown in FIG. 4.

By comparing FIGS. 2, 3, and 4, it will be apparent that the auxiliary magnet body or ring body 11 together with block 28 secured thereto is inserted in magnet body 2 and then secured to the magnet body by screws 21, the insulating block 28 being accommodated in slot or aperture 35 which is open to the back wall 18 and to the periphery of the magnet body 2. It will, of course, be understood that suitable connections are made between metallic prongs 26 and 27 and the coil ends.

Having thus described my invention, I am aware that various changes may be made without departing from the spirit thereof and, accordingly, I do not seek to be limited to the precise illustration herein given except as set forth in the appended claims.

I claim:

1. In an electromagnet, a main magnet body having a face channel and an auxiliary magnet body of magnetic material having a peripheral channel with radial flanges and a solenoid coil wound therein between said flanges, said auxiliary body being rem-ovably disposed within the channel of said main body, means comprising longitudinally extending collars secured to a face of said auxiliary body and being disposed within respective bores 35 provided in said main body, said collars having internally threaded bores, and respective screws passing into said main body and into said collars to secure said auxiliary body to said main body.

2. In an electromagnet, a ringlike main magnet body of magnetic material and an auxiliary ring-like magnet body of magnetic material having a solenoid coil therein, said main magnet body having a face channel and said auxiliary magnet body being removably insertable in said channel, means for detachably securing said auxiliary magnet body to said main magnet body comprising longitudinally removable fastening elements intermediate said bodies, means for eifecting detachable electrical connection to said solenoid coil comprising an insulating block carried by said auxiliary body, said main body having a portion of its material removed for accommodating said block when said bodies are assembled, said block carrying electrical contact elements for removable connection to cable terminals.

3. In an electromagnet, a magnet body having a channel in the face thereof, an auxiliary magnet body having a channel in the periphery thereof, a solenoid coil in said latter channel, said auxiliary magnet body being disposed in the channel of said magnetbody, means for effecting detachable connections to said solenoid coil and means for detachably connecting said auxiliary magnet body to said magnet body, said last mentioned means comprising at least one internally threaded collar integrally connected to said auxiliary body, said magnet body having a bore for receiving said collar and bore for receiving a screw from exteriorly of said magnet body to threadedly engage Within said collar, whereby said auxiliary body may be readily attached or detached within said magnet body.

4. An electromagnet comprising a magnet body of magnetic material having a channel therein opening inone direction, a solenoid coil support ring of magnetic material having a channel opening in a direction normal to said first-mentioned direction and having a solenoid coil a "2 in said latter channel, said support ring being movable into and out of the channel of said main body whereby said solenoid coil is substantially surrounded by magnetic material when said ring is disposed therein, means for effecting electrical connection to said solenoid coil when said support'ring is in said magnet body and for securement of said ring to said magnet body. I

5. In an electromagnet, a magnet body of magnetic material having a channel in a face thereof, an auxiliary magnet body of magnetic material having a peripheral channel and a solenoid coil therein, said auxiliary magnet body being disposed in the channel of said magnet body whereby said solenoid coil is substantially surrounded by magnetic material, said auxiliary magnet body being constructed and arranged to be :slidable as a unit into said channel of said magnet body for ready removal and replacement, and means for effecting detachable electrical connections to said solenoid coil, and longitudinally removable means for fastening said auxiliary magnet body to said magnet body, and accessible at a face opposite to said channel face.

6. In an electromagnet as set forth in claim 2 said auxiliary magnet body having a peripheral channel and said solenoid coil being disposed therein, whereby said coil is substantially surrounded by said magnetic material when said bodies are assembled.

7. In an electromagnet as set forth in claim 5, said detachable connection means comprisin'g a prong receiving receptacle carried by said auxiliary magnet body.

References Cited by the Examiner UNITED STATES PATENTS 2,813,232 11/57 Lillquist 317l58 2,914,714 11/59 Pierce et al. 3l7l71 2,921,242 1/60 Leitch 317-158 3,016,580 1/62 Jaeschke 192-84 JOHN F. BURNS, Primary Examiner. 

1. IN AN ELECTROMAGNET, A MAIN MAGNET BODY HAVING A FACE CHANNEL AND AN AUXILIARY MAGNET BODY OF MAGNETIC MATERIAL HAVING A PERIPHERAL CHANNEL WITH RADIAL FLANGES AND A SOLENOID COIL WOUND THEREIN BETWEEN SAID FLANGES, SAID AUXILIARY BODY BEING REMOVABLY DISPOSED WITHIN THE CHANNEL OF SAID MAIN BODY, MEANS COMPRISING LONGITUDINALLY EXTENDING COLLARS SECURED TO A FACE OF SAID AUXILIARY BODY AND BEING DISPOSED WITHIN RESPECTIVE BORES PROVIDED IN SAID MAIN BODY, SAID COLLARS HAVING INTERNALLY THREADED BORES, AND RESPECTIVE SCREWS PASSING INTO SAID MAIN BODY AND INTO SAID COLLARS TO SECURE SAID AUXILIARY BODY TO SAID MAIN BODY. 